Microbiology and Infection Control Flashcards

What is the significance of 'vegetative' versus 'sporulating' states in bacteria as they relate to susceptibility to disinfectants and sterilants?

Answer: Vegetative (actively growing/metabolizing) bacteria are readily killed by standard disinfectants and sterilants; sporulating (dormant spore) forms are extraordinarily resistant and require sterilization for elimination

Vegetative bacteria are metabolically active and susceptible to disinfectants. When conditions are unfavorable, some bacteria form dormant spores that are extraordinarily resistant to heat, chemicals, and drying — requiring sterilization rather than just disinfection.

What is the difference between bacteriostatic and bactericidal agents, and how does this distinction matter in instrument reprocessing?

Answer: Bacteriostatic agents inhibit bacterial growth (reversible); bactericidal agents kill bacteria (irreversible). In reprocessing, bactericidal agents are required — inhibiting growth is insufficient for making instruments safe for patient use

Bacteriostatic agents inhibit growth without killing; bactericidal agents kill. For instrument reprocessing, bactericidal activity (or better — sterilization) is required, as inhibiting growth is insufficient to protect patients.

What type of infection do Candida and Aspergillus species represent, and why are immunocompromised patients particularly at risk in healthcare settings?

Answer: Fungal infections — Candida causes mucosal/bloodstream infections while Aspergillus causes respiratory infections particularly in immunocompromised patients whose defenses cannot contain environmental fungal spores

Candida and Aspergillus are fungi causing serious opportunistic infections in immunocompromised patients. Aspergillus spores are ubiquitous in the environment, making infection control during construction/renovation near immunocompromised patients critical.

What is antibiotic resistance, and how do healthcare-associated pathogens such as VRE and MRSA pose challenges for infection control in the CSSD?

Answer: Antibiotic resistance means the organism resists antibiotic drug treatment but remains susceptible to standard sterilization and disinfection; VRE and MRSA require standard reprocessing plus contact precautions in clinical areas

Antibiotic resistance confers resistance to drug treatment, not to heat-based sterilization or disinfectants. VRE and MRSA are eliminated by standard reprocessing. The challenge is clinical management and contact precautions, not instrument sterilization.

How do prions differ from conventional infectious agents, and what makes them uniquely challenging for the CSSD?

Answer: Prions are misfolded proteins with no nucleic acid that resist heat, radiation, standard chemical disinfection, and many sterilization processes — requiring specialized protocols or instrument destruction for high-risk procedures

Prions are infectious misfolded proteins (no DNA/RNA) that are uniquely resistant to standard sterilization, radiation, formaldehyde, and most disinfectants — requiring specialized decontamination approaches for instruments used in prion disease procedures.

What role does the chain of infection play in understanding healthcare-associated infection prevention in the CSSD?

Answer: The chain of infection describes the six links required for infection transmission (infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host); breaking any link prevents infection, and CSSD interrupts multiple links simultaneously

The chain of infection describes the six links required for infection to occur. The CSSD interrupts multiple links: eliminating infectious agents (sterilization), removing reservoirs (decontamination), and preventing modes of transmission (proper packaging and sterile distribution).